(1) Equipment and materials
The greenhouse adopts reinforced concrete arch frame, which does not need column support. The room is spacious and convenient for facility installation and various operations. The nutrient solution pool is located at one end of the greenhouse, below the ground, with a length of 3m and a width of1.2m.. A nutrient solution pool with a depth of1.6m.. The structure is made of brick and mud, and the inner wall and bottom are smooth, so the liquid will not leak out. The outer packaging of the cultivation column is made of plastic woven cloth, which is rolled into a barrel shape with a diameter of 15cm and a length of 1.7m, and stitched, with the upper opening and the lower opening closed. Other equipment includes small circulating pump, filter, water main pipe with a diameter of about 5 cm, water capillary, bypass, dripping shower head, iron ring on cultivation column, pipe plug, iron wire, etc.
(2) Installation of columns
In the greenhouse, a cultivation tank with a length of 4.8 meters, a width of 0.5 meters and a depth of 12 cm was bricked in the north-south direction. A working channel with a width of 0.5m is left between the grooves. The southern end of the culture pond is bricked into a 0.5-meter-wide backwater ditch. The bottom and four walls of each culture pond are covered with plastic films to prevent nutrient solution from leaking, and then ceramsite with a thickness of 4 cm is sprinkled. An iron bar with a height of 1.95 meters passes through the bottom of the barrel and is connected with plastic woven cloth around it. Fill the bucket with organic matrix along the upper opening until it reaches the top. Then add a circular iron ring to the upper opening and sew it with the plastic woven cloth on the upper opening. The iron bar of the cultivation column support frame will be higher than the cultivation column barrel by more than 20 cm, and the top of the iron bar is used to install the dripping shower head. In this way, a complete culture column is formed.
(3) Assembly and fixation
The assembled cultivation columns are put into cultivation tanks, and each cultivation tank has two rows of columns, with six columns as a row. Each row of columns is connected by thick iron wire in the north-south direction, and both ends of the iron wire are fixed on the greenhouse building to prevent lodging. The axial distance between two rows of columns in the cultivation pot is 0.75cm, and the axial distance between two rows of columns in the cultivation pot is1m.
(4) connecting a nutrient solution conveying system
The nutrient solution conveying system is sequentially connected with a liquid storage tank, a circulating pump, a filter, a main pipeline, a bypass, a capillary, a dropper, a culture column, a culture tank, a recovery ditch and a liquid storage tank. The main pipeline of the nutrient solution conveying system is arranged along the upper end of the north wall of the greenhouse. Capillary tubes and drippers are hung on the top of the culture column, and the end of each capillary tube is blocked with a plug.
(5) preparing nutrient solution
The nutrient solution ratio of leafy vegetables (1 ton of water): calcium nitrate 236 g, potassium nitrate 404 g, ammonium dihydrogen phosphate 57 g, magnesium sulfate 123 g, chelated iron 16 g, boric acid 1.2 g, manganese chloride 0.72 g and zinc sulfate 0.09.
(6) Crop planting
Simple soilless stereo cultivation is generally suitable for short-leaf crops, such as lettuce, rape and celery. Before planting crops, punch holes in the cultivation column, and evenly punch 40 holes in the column with the height of 1.7 meters. Water is pumped into the culture column through the nutrient solution conveying system to make the matrix in the column reach a wet state. Plant the vegetable seedlings that need to be cultivated in the greenhouse in the cultivation holes.
(7) Seedling management
Clear water should be introduced within three days after planting, every half hour 1 time in summer and every 1 hour 1 time in winter, and the duration of water introduction should not be less than 8 minutes, so as to slow down the seedling speed. After the seedlings are delayed, the nutrient solution is prepared in the nutrient solution pool and transported to the cultivation column regularly. At the initial stage of planting, the concentration of nutrient solution is lower, and the liquid inlet interval is 1 hour, 1 time. After that, the concentration of nutrient solution should be raised to the required level, and the feeding interval should be controlled at 2 hours 1 time, and the feeding duration is generally 8 minutes.